and rats, as well as the serum cholesterol and
postprandial (after meal) blood glucose in
humans (MARTINDALE).3–5 When included
at different levels in the diets of chickens,
guar gum has been demonstrated to cause
growth depression, though with inconsistent
results. It also reduced the metabolizable
energy of the diets in which it was
included.3,6,7
Guar gum does not seem to be digested by
animals.^3
In women, one study found that ingestion
of guar gum led to permanent weight loss,
but did not influence serum lipids in hyper-
cholesterolemia.^8 Similar results were
noted in male patients and elderly pa-
tients.9–11 However, positive results are
reported in the use of guar gum as a long-term
dietary supplement in control of hypercholes-
terolemia in diabetics.10,12–14 Long-term
administration (21 g/day) produced a sus-
tained improvement in control of type 2 dia-
betes, with significantly lower serum total
and LDL cholesterol concentrations.^15
An average reduction of 14% total cholesterol
levels was observed in doses of 10 g b.i.d.
immediately before meals as well as a reduc-
tion in postprandial glucose levels.^16 Other
studies have produced similar positive results
including a recent one in alloxan-induced
diabetic rats.10,12,17,18
A blood pressure lowering effect (8% sys-
tolic; 7% diastolic) has been observed in
overweight men with mild hypertension.^19
TOXICOLOGY
Flatulence has frequently been reported as a
side effect to guar gum dietary supplementa-
tion.^20 Occupational asthma has been reported
in subjects working with industrial production
of guar gum.^21 A severe case of contact urti-
caria has recently been linked to guar gum
present in a local anesthetic gel.^22
Guar gum did not produce teratogenic
effects in rats.^23 A human study found that
guar gum consumption in diabetic mellitus
patients did not adversely affect mineral
balance.^24USESMedicinal, Pharmaceutical, and Cosmetic.
It is used as a binding and disintegrating agent
in tablets and as a thickener in lotions and
creams;^25 also used as an appetite depressant
and in certain antihypercholesterolemic
preparations.Food. Used extensively as a thickener,
stabilizer, suspending agent, and binder of
free water in many food products, including
nonalcoholic beverages (e.g., fruit drinks),
frozen dairy desserts (especially ice cream
and sherbets where it binds free water to
prevent ice crystals formation), baked goods,
gelatins and puddings, meat and meat pro-
ducts, condiments and relishes, breakfast cer-
eals, cheeses (especially soft cheeses and
spreads), milk products, soups, sweet sauces,
gravies, snack foods, and processed vegeta-
bles, among others.26,27 Highest average
maximum use level reported is about 1% in
breakfast cereals (11,260 ppm), sweet sauces
(9000 ppm), and processed vegetables
(10,747 ppm).Dietary Supplements/Health Foods. Cap-
sules, tablets, powder, and other product forms
have, until recently, been widely used in
weight loss formulations. Guar gum was
blamed for causing esophageal obstruction.
A death has been attributed to the use of one
guar gum tablet product, which apparently
swelled in the esophagus, indirectly resulting
in complications that caused the fatality.^28
Major adverse reactions appear to result
from product formulations (tablets) that
dissolve in the mouth or esophagus before
they reach the stomach. The FDA issued
regulatory letters to manufacturers of guar
gum capsules or tablets. Products that includ-
ed claims implying use in weight loss, appetite
suppression, or cholesterol or blood glucose348 Guar gum